Method and system for feature extraction and decision making from series of images

ABSTRACT

Apparatus and methods comprise examination of a subject using images of the subject. The images can provide a non-invasive analysis technique and can include a plurality of images of a portion of the subject at different times a temperature stimulus applied to the subject. An image of the portion of the subject can be aligned such that each pixel of the image corresponds to the same point on the subject over a sequence of images of the portion. The sequence of images can be processed after aligning the images such that data is extracted from the images. The extracted data can be used to make decisions regarding the health status of the subject. Additional apparatus, systems, and methods are disclosed.

CLAIM OF PRIORITY

This application claims the priority benefit of U.S. ProvisionalApplication Ser. No. 61/648,927, filed 18 May 2012, entitled “A METHODAND SYSTEM FOR FEATURE EXTRACTION AND DECISION MAKING FROM SERIES OFIMAGES,” which application is incorporated herein by reference in itsentirety.

GOVERNMENT INTEREST STATEMENT

This invention was made with U.S. Government support under grant numberR25 CA153825 awarded by the National Institute of Health (CNTC). TheUnited States Government has certain rights to the invention.

FIELD OF THE INVENTION

This invention relates generally to the field of non-invasivediagnostics.

BACKGROUND

Skin cancer is a serious medical condition that can be fatal undercertain situations if not properly treated. In most cases when thisillness is diagnosed, a patient will go to the doctor to report a skinabnormality (discoloration, growth, etc.). After a visual inspectionthat determines that the abnormality could be malignant, the doctortypically will perform a biopsy, wherein a portion or the entirety ofthe abnormality is removed. This specimen is then processed with knowntechniques and examined by an expert to determine whether or not it is amalignant cancer. However, in an effort to conservatively catch allincidents of cancer, doctors tend to perform the biopsy procedure in anycase where there is doubt. Therefore, the large majority (>90%) ofbiopsies that are taken turn out to be healthy tissue. This causes unduesuffering and discomfort to healthy individuals. In addition, the riskof not catching serious skin cancers early enough increases when doctorstry to avoid this intrusive procedure in the first place.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a block diagram of an example imaging and analysis systemoperable to detect skin cancer, in accordance with various embodiments.

FIG. 2 shows example features of a process flow to make decisions basedon images, in accordance with various embodiments.

FIG. 3 shows features of an example method of examining a subject usingimages of the subject, providing a non-invasive analysis technique, inaccordance with various embodiments.

FIG. 4 depicts a block diagram of features of an example system operableto examine a subject using images of the subject, providing anon-invasive analysis technique, in accordance with various embodiments.

DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration and not limitation, various exampleembodiments of the invention. These embodiments are described insufficient detail to enable those skilled in the art to practice theseand other embodiments. Other embodiments may be utilized, andstructural, logical, and electrical changes may be made to theseembodiments. The various embodiments are not necessarily mutuallyexclusive, as some embodiments can be combined with one or more otherembodiments to form new embodiments. The following detailed descriptionis, therefore, not to be taken in a limiting sense.

In various embodiments, a complete imaging and analysis system for thedetection of skin cancer may offer doctors and medical technicians anentirely passive (non-intrusive) way of detecting skin cancer. Such animaging and analysis system is based on the principle that healthytissue has different thermal properties than diseased tissue. Forexample, when the skin is cooled, healthy tissue will return to itsoriginal temperature at a different rate than diseased tissue. Byexamining these differences, the system can provide doctors a betteridea whether the abnormality is or is not malignant. However, such asystem or a system similar to an embodiment of a system operable todetect skin cancer may also be used in extremely different applications,such as, for example, but not limit to embodiments of systems toclassify minerals in rock for a geological survey.

FIG. 1 shows a block diagram of an example embodiment of imaging andanalysis system 100 operable to detect skin cancer. System 100 maycomprise several components or stages, which may be referred to assystems or subsystems. These systems or subsystems can work together toprovide a function of the entire system 100. The stages of system 100can include a system 110 to control temperature, a system 120 to mark asubject, a system 130 to acquire images, a system 140 to align theimages, a system 150 to process the acquired images, and a system 160 toview information. Two or more of the systems can be structured as anintegrated system. For example, subsystems of system 100 can bestructured as permutations of these systems in an integrated format.

System 110 to control temperature can be arranged as a system forcontrolling temperature so that the thermal response of a subject can bemeasured. The subject may be skin of an individual. Controllingtemperature can include, for example, cooling a subject, such as skin,from an ambient temperature or from a temperature to which the subjecthas been heated. System 120 to mark a subject can be arranged as asystem for marking the subject, such as skin, to enable a registrationprocess. System 130 to acquire images can be arranged as a system foracquiring images, where the images may be traditional single colorimages, traditional multi-color images, infrared images,multispectral/hyperspectral images, other types of images orcombinations thereof. System 140 to align the images can be arranged asa system for aligning the images with each other to account for subjectmotion, such as a patient motion and/or camera motion. System 140 toalign the images can be structured to operate on stored instructions toalign the images according to an algorithm performed by execution of theinstructions. An algorithm is herein, and generally, conceived to be aself-consistent sequence of steps, and/or rules governing operation ofthe steps, leading to a result. The aligning of the images can providefor registering images. System 150 to process the acquired images can bearranged as a system for processing the acquired images to extractinformation. System 150 to process the acquired images can be structuredto operate on stored instructions to process the images according to analgorithm performed by execution of the instructions. System 160 to viewinformation can be arranged as a system for viewing the information in amanner that is meaningful to an expert that deals with the subject beinginvestigation. For system 160 disposed as part of a system to detectcancer, the information can be provided in a manner that is meaningfulto a medical expert. Though imaging and analysis systems, as taughtherein, may be used in non-medical applications, the followingdiscussions deal with a system operable to detect skin cancer. Suchdiscussions, appropriately modified, may be applied to non-medicalapplications.

In an embodiment, system 110 to control temperature can be used todetect skin cancer. The detection of skin cancer can be conducted byexamining differences in thermal response of different parts of theskin. In other words, a system can use system 110 to control temperatureto detect and analyze the rate of warming of skin that has been cooleddown. To perform such a function, system 110 to control temperature caninclude cooling and/or heating components that can cool or warm the skinquickly, while at the same time providing uniform cooling or heating tothe region of skin that is being imaged by, for example, system 130 toacquire images. The heating or cooling images can be captured by aninfrared camera. System 110 to control temperature may include coolingand/or heating components that not only cool or warm the skin quickly,but can also cool or warm the skin comfortably. Uniformity can beimportant to have all the cells at the same initial temperature.

In an embodiment, a pressurized air system that blows cold air on thepatient's skin can be used. The cooling system may consist of a vortextube that provides a blast of cold air whose temperature and outputvolume depend on the system parameters such diameter of opening, shapeof nozzle, and inlet pressure. Another approach to cooling or heatingcan include the use of a thermal spreader to achieve cooling viaconduction, convection, or radiation. The thermal spreader could beplaced in an on status temporarily and removed before data acquisitionor could be in the field of view of an imaging system such as system 130to acquire images. Pulsed heating or cooling may also be used withdifferent durations to study the differential temperature response of alesion and healthy skin.

System 120 to mark a subject, such as skin, and system 140 to align theimages are related to the process of registering the images acquiredusing system 130 to acquire images. System 150 to process the acquiredimages can provide an information extraction process requiring that allof the images are substantially lined up with respect to each other, sothat a specific pixel in each image corresponds to the same part of theskin on the patient. In this way, information such as temporal trends ateach selected point on the skin's surface can be measured. However, inpractice the patient's skin undergoes natural motion (because ofbreathing, involuntary movement, etc.) and the camera may not beperfectly static. These events produce apparent motion in each of thecaptured image frames, which must be removed if the informationextraction is to be performed successfully.

System 120 to mark a subject can be used to first apply calibrationmarkers to the patient's skin that enable the registration of the imagesby an algorithm of system 140 to align the images. These are importantto a proper working system, since without the calibration markers, it isdifficult (if not impossible) to register the images by system 140 toalign the images. These markers must be clearly visible against the skinin the wavelength measured by the imaging device, such as a camera, ofsystem 130 to acquire images. In other words, the marker should clearlystand out in the final image when compared to the surrounding skin.

In an embodiment, the marker contains sharp corners that can be clearlyresolved in the captured images. These corners can provide features thatwill help in the registration process when used by an algorithm ofsystem 140 to align the images. It was found experimentally that puttingthermal insulation between the marker and the skin helped the markerstand out better in the final infrared (thermal) images. For example,tape can be used as the thermal insulation. Different materials withdifferent emissivity and thermal conductivity can be used to make goodmarkers. For markers to be visible in all frames, markers having a highemissivity can be used in all the frames. Reheating or re-cooling of thesurrounding skin from the marker should be avoided. Similarly, reheatingor re-cooling of the marker must be avoided.

In an embodiment, system 130 to acquire images can include an imagingdevice to capture images of the skin's surface. An imaging device can bea camera or other similar device to capture images of the skin'ssurface. To study the skin's response over time, the camera or similardevice includes the capability to acquire video or a sequential seriesof frames, where the time of each is known or can be computed. In anembodiment, a camera has the capability to acquire frames reasonablyclose together over a selected time period. The time period may be, butis not limited to, about 3-5 minutes. In a non-limiting example, acamera having the capability to acquire 10 frames per second, forexample, for a period of about 3-5 minutes can be used. However, aselected number of frames over a selected time period, other than theabove examples, can be implemented, depending on the application. Thecamera or other imaging device can be arranged to capture an abnormalityin the skin being investigated, the skin markers identified by a system,as system 120 to mark a subject, as well as some of the healthy tissuesurrounding the abnormality.

The imaging device may be provided in different formats. The imagingdevice can be an infrared camera, which can measure the temperature ofthe skin. The imaging device can be a device capable of measuring aresponse from 300 microns to 3 mm covering the entire electromagneticspectra. For example, for measuring temperatures, a mid wave infraredcamera, for example 5 μm, and a long wave infrared camera, for example10 μm, can be used.

The imaging device can include a number of different types of cameras.For example, the imaging device can include an infrared camera and astandard color camera. The cameras may both be taking picturesthroughout the entire period of the acquisition (either simultaneouslyor asynchronously). Alternatively, the color camera may capture a singlepicture with the rest of the acquisition being performed by the infraredcamera. Having two kinds of pictures makes the system more useful inpractice, since doctors are normally accustomed to looking at colorimages of the skin and are unfamiliar with infrared images. Therefore,the color images help the doctor recognize the skin features on theinfrared images better.

The imaging device, such as a camera, can have spacers or handles tomake it easier to align with the skin and to take pictures consistentlyfrom a fixed distance to the skin. The imaging devices, such as cameras,can be mechanically, electronically, or optically synced to capture theimages at the same point of time.

Stage 140 to align the images can include an algorithm for registeringimages. The patient's skin will undergo involuntary motion. Since themotion in the series of images is not a desirable feature and must beeliminated, the images acquired over time need to be registered oraligned so that each pixel of the image corresponds to the same point onthe skin over the entire sequence. For this reason, a registrationalgorithm uses the markers from system 120 to align the images to eachother. In an embodiment, the algorithm uses a corner detection techniqueto extract the sharp corners from the image, many of which correspond tothe skin markers from using system 120 to mark a subject. Cornerdetection technique is a known technique. The algorithm treats thesesharp corners as features and tracks them over all the frames. Thealgorithm is structured to use knowledge that these features, althoughthey are moving from frame to frame, all correspond to the same point onthe skin surface. Therefore, it solves for a transformation that mapseach single feature to its correct location in a reference image. In anexample, a homography can be used to compute this transformation, whichassumes that the skin is on a plane. Once this transformation has beencomputed, it can be applied to all the pixels in the image. Sometimes,re-sampling may be performed to compute the final pixel values.Effectively, this registers the skin from one image to another. In anembodiment, with registration performed on the infrared images, thealgorithm can work entirely on scalar values. In another embodiment,color images can be registered to the infrared images in a similarmanner.

Stage 150 to process the acquired images can use an algorithm forprocessing the acquired images to extract information. Once the imageshave been registered, system 150 to process the acquired images performsalgorithms on the aligned image sequence in order to extractinformation. In an embodiment, the information to be extracted is“yes/no” binary values that suggest the presence of malignant cancer. Inanother embodiment, the information can be a probability value (a realnumber, not binary) that may indicate the chance of malignancy.

The following provides a non-limiting example of an algorithm to extractinformation. When using an infrared camera, the temperature of the skinis being imaged at every point in the image over time. Therefore, foreach point on the skin, a temperature vs. time curve that indicates howthe skin's temperature at that point changed over time can be obtained.A mathematical model can be fitted to this data to generate a list of nparameters that describe the curves at each selected point. The modelcan be, but is not limited to, a simple polynomial model, an exponentialmodel, a logarithmic model, a model using orthogonal basis functions, amodel using non-orthogonal basis functions, or a physiologically basedmodel. These n parameters can then be used to classify the differentparts of the skin with various segmentation/clustering algorithms. It isimportant to also consider the fact that not all the areas of the skinare at the same initial temperature, which may be due to variationscaused by the cooling or heating systems. The algorithm may provide anapproach to compensate for the offset associated with the variousdifferential temperature curves.

For example, if a model is fitted with n parameters to each selectedpoint on the skin, each selected point on the skin can essentially beconsidered as embedded within an n-dimensional space. If some parts ofthe skin are known to be healthy, such as the healthy tissue surroundingthe abnormality, these parts can be used to potentially classify thepoints into healthy tissue or malignant tissue. Algorithms such as, butnot limited to, principal component analysis (PCA) may be used for sucha procedure. PCA effectively would linearly project the n-dimensionalparameter space into an orthogonal basis that would separate outfeatures more strongly with fewer parameters.

System 160 to view information can be arranged for viewing theinformation in a manner that is meaningful to a medical expert. Once thealgorithms of stage 150 have been applied to the aligned images, system160 allows a medical expert to understand the results of the analysis.System 160 can use stored instructions that can be executed by aprocessor to present the information to the medical expert. For example,executable instructions can be used to plot the temperature trends as afunction of a point (or many points) on the skin, where the point(s) areselected by the user using a user selector mechanism such as, but notlimited to, a mouse. The executable instructions may assign colors tothe representation of the information such that the images can becolor-coded using the n-dimensional parameter space discovered in stage150. This procedure may be performed, for example, by producing nfalse-color images showing the magnitude of each component. Computervision/machine learning algorithms may also be applied to this data tofurther segment and highlight features and structures in the data.

In an embodiment, system 160 to view information may provide avisualization system that may include a full mouse-driven navigationcontrol to allow a doctor to rotate the skin to view it from differentdirections. Also, if the sample is later biopsied, the visualizationdata can be used to align to the scan of the biopsy to allow for amedical expert to correlate physical features to temperature patterns orother patterns on the skin. This would allow for a greater understandingfor the processes involved in malignant cases. In an embodiment, system160 to view information may be a text-based indicator that indicates tothe user “yes” or “no” as to whether to biopsy the sample.

FIG. 2 shows example features of a process flow to make decisions basedon images. At 242, variable v is assigned to each pixel of an image.Though a 4×4 image is shown for presentation purposes, the process flowmay be applied to images of different sizes. At 244, pixels with aseries of images with variable v changing as a function of variable uare provided. For example, variable v can change as a function oftemperature and/or time. Though a 4×4 image is shown for presentationpurposes, the process flow may be applied to images of different sizes.At 246, image registration is preformed. At 248, plots ofparameterization of variable v versus variable u can be generated. At250, feature extraction can be performed to obtain single or multipleparameters that can quantify the series of images. At 260, visualizationof data from the feature extraction can be performed. At 270, decisionscan be made based on confidence levels of parameters from the featureextraction and data visualization.

FIG. 3 shows features of an embodiment of an example method of examiningof a subject using images of the subject, providing a substantiallynon-invasive analysis technique. The example method may be conductedwith a system that includes one or more component systems similar to oridentical to the system components of system 100 of FIG. 1 or system 400of FIG. 4. At 310, images of a subject are acquired. The images caninclude a plurality of images of a portion of the subject at differenttimes. The portions may be a part of the subject under investigation.For example, the portion may be a lesion on the skin of the subject. Theportion may be healthy tissue and tissue under investigation. Theportion may include the entire subject. Acquiring the images can includeusing a plurality of imaging devices. The plurality of imaging devicescan include an infrared camera and a camera that provides color images.

At 320, an image is aligned such that each pixel of the imagecorresponds to a same point on the subject over a sequence of images ofthe portion. The image being aligned may be an image of the portion ofthe subject. The method can include applying one or more calibrationmarkers to the subject such that the one or more calibration markers areused when aligning the image of the portion of the subject. The one ormore calibration markers can be visible against the portion of thesubject in a wavelength range measured by an imagining device thatcaptures the images of the subject. The one or more calibration markerscan contain sharp corners resolved in the acquired images, where the oneor more calibration markers are used in aligning the image of theportion of the subject. Aligning the image of the portion of the subjectcan include using a corner detection technique to extract sharp cornersfrom the image. Aligning the image of the portion of the subject caninclude performing a transformation that maps each feature of the imageto its correct location in a reference image. Performing thetransformation can use a homography to compute the transformation underan assumption that the subject is on a plane.

At 330, the sequence of images is processed after aligning the imagessuch that data is extracted from the images. Processing the sequence ofimages may include, for each selected point on the subject, generatingtemperature vs. time data, fitting a model to the data, generating alist of parameters corresponding to the temperature vs. time data ateach selected point using the model, and using one or moresegmentation/clustering techniques to classify different parts of thesubject. Using one or more segmentation/clustering techniques toclassify different parts of the subject can include classifying pointson skin as healthy tissue or malignant tissue.

At 340, data corresponding to the subject is presented on a displayunit. The data can be presented following the processing of thesequence. Presenting the data can include color-coding the images on thedisplay unit. The color-coding can be conducted using a n-dimensionalparameter space generated from processing the sequence of images afteraligning the images. Presenting the data can include rotating, on thedisplay unit, an image of a skin subject to view the skin subject fromdifferent directions. Presenting the data can include, on the displayunit displaying visualization data of a skin subject, aligning thevisualization data to a scan of a biopsy of the skin subjectcorresponding to the visualization data of the skin subject.

The method can include applying a set of temperature stimuli to theportion of the subject, capturing the images of the portion at thedifferent times with respect to applying the set of temperature stimuli,and determining a status of the portion of the subject from processingthe sequence of images after alignment. Determining the status of theportion of the subject can include determining a rate of warming thesubject after the subject has been cooled. Applying the set oftemperature stimuli to the portion of the subject can include applyingpulsed heating or cooling with different durations to skin, includinghealthy skin and a lesion, to analyze a differential temperatureresponse of the lesion and the healthy skin. Determining the status ofthe portion of the subject can include determining a presence ofmalignant cancer or a probability value indicating a chance ofmalignancy. Various techniques discussed herein or combinations thereofcan be used in the example method of examining a subject using images ofthe subject or in other methods to examine a subject using images of thesubject in a manner similar to the example method or portions thereof.

In various embodiments, a machine-readable storage device can haveinstructions stored thereon, which instructions when executed by one ormore processors of a machine, cause the machine to perform operations,the operations comprising any of the features of methods of examining asubject using images of the subject and conducting operations based onthe images in a manner identical to or similar to the methods andschemes described herein. For example, the instructions can includeacquiring images of a subject, the images including a plurality ofimages of a portion of the subject at different times; aligning an imageof the portion of the subject such that each pixel of the imagecorresponds to a same point on the subject over a sequence of images ofthe portion; processing the sequence of images after aligning the imagessuch that data is extracted from the images; and presenting datacorresponding to the subject on a display unit, following the processingof the sequence. Further, a machine-readable storage device, herein, isa physical device that stores data represented by physical structurewithin the device. Examples of machine-readable storage devices include,but are not limited to, read only memory (ROM), random access memory(RAM), a magnetic disk storage device, an optical storage device, aflash memory, other electronic, magnetic, and/or optical memory devices,and combinations thereof.

FIG. 4 depicts a block diagram of features of an embodiment of anexample system 400 operable to examine a subject using images of thesubject, providing a non-invasive analysis technique. System 400 cancomprise an image acquisition system 430, an alignment system 440, aprocessing system 450, and a display system 460. Image acquisitionsystem 430 is operable to acquire images of a subject including aplurality of images of a portion of the subject at different times.Image acquisition system 430 may be similar or identical to system 130to acquire images of FIG. 1. Alignment system 440 is operably coupled toimage acquisition system 430, where alignment system 440 is arranged toalign images acquired by image acquisition system 430 such that, foreach image, each pixel of the image corresponds to a same point on thesubject over a sequence of images of the portion. Alignment system 440may be similar or identical to system 140 to align images of FIG. 1.Processing system 450 is operably coupled to the alignment system and isarranged to process the images, after aligning the images, such thatdata is extracted from the images. Processing system 450 may be similaror identical to system 150 to process acquired images. Display system460 is operably coupled to processing system 450. Display system 460 isoperable to present data corresponding to the subject on a display unit462 following the processing of the images.

System 400 can include one or more sources 412 arranged to apply a setof temperature stimuli to the portion of the subject. System 400 caninclude temperature controller 410 to control operation of sources 412.Temperature controller 410 can be structured to apply pulsed heating orcooling with different durations to skin, including healthy skin and alesion. This control may be realized with sources 412 in conjunctionwith circuitry to activate and turn off sources and timing circuitry tocontrol the duration in which sources 412 are on. Temperature sensorscan be used with the timing circuitry.

Image acquisition system 430 can be arranged to capture the images ofthe portion at the different times with respect to application of theset of temperature stimuli using the sources 412. Image acquisitionsystem 430 can include a plurality of imaging devices 435. The pluralityof imaging devices 435 can include an infrared camera and a camera thatprovides color images. Image acquisition system 430 can include one ormore imaging devices 435 with one or more optical elements to captureimages of the subject. The optical elements can include one or more of aspectral filter, a polarizer, or a neutral density filter. The spectralfilter can include a low pass filter, a high pass filter, a bandpassfilter, or a notch filter. The polarizer used can have an anglecontinuously variable from 0 degrees to 360 degrees. The neutral densityfilter can be operable to change a dynamic range of an image beingcaptured by its corresponding imaging device.

System 400 can include a marker system 420 to identify markers appliedto the subject. The markers can be realized as one or more calibrationmarkers applied to the subject in a manner in which alignment system 440is operable to use to align the image of the portion of the subject. Theone or more calibration markers can be structured to be visible againstthe portion of the subject in a wavelength range measured by animagining device of image acquisition system 430 that captures theimages of the subject. The one or more calibration markers can containsharp corners resolvable in the acquired images, where the sharp cornerscan be used in aligning the image of the portion of the subject. Spatialcoordinates of a reference marker can be used to correct for voluntaryor involuntary movement of a portion of the subject under investigation.

Alignment system 440 can include instructions to perform a cornerdetection technique to extract sharp corners from the image. Alignmentsystem 440 can include instructions to perform a transformation thatmaps each feature of the image to its correct location in a referenceimage. The instructions to perform the transformation can includeinstructions to use a homography to compute the transformation under anassumption that the subject is on a plane.

Processing system 450 can be structured to be operable to determine arate of warming a subject after the subject has been cooled. Processingsystem 450 can be structured to determine a status of the portion of thesubject from processing the images after alignment. Processing system450 can be arranged to analyze a differential temperature response of alesion and healthy skin of a subject. Processing system 450 can beoperable to determine a presence of malignant cancer or a probabilityvalue indicating a chance of malignancy. Processing system 450 caninclude instructions to process the sequence of images includinginstructions to, for each selected point on the subject, generatetemperature vs. time data; to fit a model to the data; to generate alist of discrete and continuous parameters corresponding to thetemperature vs. time data at each selected point using the model; and touse one or more segmentation/clustering techniques to classify differentparts of the subject. The instructions to use one or moresegmentation/clustering techniques can include instructions to classifypoints on skin as healthy tissue or malignant tissue.

Display system 460 can be structured to be operable to present data withrespect to the subject by color-coding the processed images on displayunit 462. The color-coding can be conducted using a n-dimensionalparameter space generated from processing the sequence of images afteraligning the images. Display system 460 can be operable to rotate, ondisplay unit 462, an image of skin of a subject such that the skin isviewable from different directions. Display system 460 can be operableto present the data on display unit 462 displaying visualization data ofthe skin such that the visualization data is aligned to a scan of abiopsy of the skin corresponding to the visualization data of the skin.

One or more components of system 400 may be realized as one or more setsof instructions stored in system 400, such as stored in memory 472, andexecuted by one or more processor(s) 471 to perform the functions ofsuch components. Such instructions can include one or more algorithms toperform specific functions. The one or more processor(s) 471 may be usedby any of the components of system 400. Alternatively, system componentsmay include their own processor. System 400 may include a database withdata disposed in memory 472 that is accessible to the components ofsystem 400. The database can be arranged to store data corresponding toa full body scan of the subject. System 400 can be arranged to conductnon-invasive operations for analysis in accordance with the methodstaught herein, and may include various of the devices discussed hereinto conduct the non-invasive operations.

System 400 may also include electronic apparatus 474 and acommunications unit 475. Electronic apparatus 474 may include circuitryto operate with various components of system 400. For example,electronic apparatus 474 may include circuitry to activate and turn offcomponents, timing circuitry to control the duration in which componentsare off or on, sensors such as, but not limited to, temperature sensors,or combinations of these circuits and sensors. Communications unit 475may be operable to provide data and/or analysis results to systems otherthan system 400.

System 400 can also include a bus 473, where bus 473 provides electricalconductivity among the components of system 400. Bus 473 can include anaddress bus, a data bus, and a control bus, each may be independentlyconfigured. Bus 473 can be realized using a number of differentcommunication mediums that may allow for the distribution of componentsof system 400. Use of bus 473 can be regulated by processor(s) 471. Bus473 may be realized as a communications network.

In various embodiments, peripheral devices 479 can include additionaldisplays, additional storage memory, and/or other control devices thatmay operate in conjunction with processor(s) 471 and/or memory 472.Processor(s) 471 may operate independently depending on an assignedfunction. Peripheral devices 479 can include a display, which may bearranged as a distributed component, that can be used with instructionsstored in memory 472 to implement a user interface to manage theoperation of components of system 400. Such a user interface may beoperated in conjunction with communications unit 475 and bus 473. Theuser interface to manage the operation of components of system 400 maybe implemented in display system 460.

Systems 110, 120, 130, 140, 150, and 160, combinations thereof, orsimilar systems, such as but not limited to those of FIG. 4, may beintegrated into a system that may provide a “home test” version ofsystems discussed herein. A person may use this “home test” system intheir home routinely to detect if there are possible dangers. The personmay be, for example, someone who is in a population that is consideredhigh risk of getting skin cancer, either by their geographical locationor skin complexion (fair skin). This kind of system may be able todetect early stages of malignant cancers before they are even visible inthe skin, and may produce a warning instructing the person to seekmedical help for further examination. This system may also be extendedto total body photography, where the differential temperature data isobtained by using an extended cooling system, single or multiplemarkers, and multiple cameras (infrared, visible etc).

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement that is calculated to achieve the same purpose maybe substituted for the specific embodiments shown. Upon studying thedisclosure, it will be apparent to those skilled in the art that variousmodifications and variations can be made in the devices and methods ofvarious embodiments of the invention. Various embodiments can usepermutations and/or combinations of embodiments described herein. Otherembodiments will be apparent to those skilled in the art fromconsideration of the specification and practice of the embodimentsdisclosed herein. It is to be understood that the above description isintended to be illustrative, and not restrictive, and that thephraseology or terminology employed herein is for the purpose ofdescription.

1. A method comprising: acquiring images of a subject, the imagesincluding a plurality of images of a portion of the subject at differenttimes; aligning an image of the portion of the subject such that eachpixel of the image corresponds to a same point on the subject over asequence of images of the portion; processing the sequence of imagesafter aligning the images such that data is extracted from the images;and presenting data corresponding to the subject on a display unit,following the processing of the sequence.
 2. The method of claim 1,wherein the method includes: applying a set of temperature stimuli tothe portion of the subject; capturing the images of the portion at thedifferent times with respect to applying the set of temperature stimuli;and determining a status of the portion of the subject from processingthe sequence of images after alignment.
 3. The method of claim 2,wherein determining the status of the portion of the subject includesdetermining a rate of warming the subject after the subject has beencooled.
 4. The method of claim 2, wherein applying the set oftemperature stimuli to the portion of the subject includes applyingpulsed heating or cooling with different durations to skin, includinghealthy skin and a lesion, to analyze a differential temperatureresponse of the lesion and the healthy skin.
 5. The method of claim 2,wherein determining the status of the portion of the subject includesdetermining a presence of malignant cancer or a probability valueindicating a chance of malignancy.
 6. The method of claim 1, whereinacquiring the images includes using a plurality of imaging devices. 7.(canceled)
 8. The method of claim 1, wherein the method includesapplying one or more calibration markers to the subject such that theone or more calibration markers are used when aligning the image of theportion of the subject.
 9. The method of claim 8, wherein the one ormore calibration markers are visible against the portion of the subjectin a wavelength range measured by an imagining device that captures theimages of the subject.
 10. The method of claim 8, wherein the one ormore calibration markers contain sharp corners resolved in the acquiredimages, the one or more calibration markers used in aligning the imageof the portion of the subject.
 11. The method of claim 1, whereinaligning the image of the portion of the subject includes using a cornerdetection technique to extract sharp corners from the image.
 12. Themethod of claim 1, wherein aligning the image of the portion of thesubject includes performing a transformation that maps each feature ofthe image to its correct location in a reference image.
 13. The methodof claim 12, wherein performing the transformation uses a homography tocompute the transformation under an assumption that the subject is on aplane.
 14. The method of claim 1, wherein processing the sequence ofimages includes: for each selected point on the subject, generatingtemperature vs. time data; fitting a model to the data; generating alist of parameters corresponding to the temperature vs. time data ateach selected point using the model; and using one or moresegmentation/clustering techniques to classify different parts of thesubject.
 15. The method of claim 14, wherein using one or moresegmentation/clustering techniques to classify different parts of thesubject includes classifying points on skin as healthy tissue ormalignant tissue.
 16. The method of claim 1, wherein presenting the dataincludes color-coding the images on the display unit, using an-dimensional parameter space generated from processing the sequence ofimages after aligning the images.
 17. The method of claim 1, whereinpresenting the data includes rotating, on the display unit, an image ofa skin subject to view the skin subject from different directions. 18.The method of claim 1, wherein presenting the data includes, on thedisplay unit displaying visualization data of a skin subject, aligningthe visualization data to a scan of a biopsy of the skin subjectcorresponding to the visualization data of the skin subject.
 19. Amachine-readable storage device having executable instructions storedthereon, which instructions when executed, causes a machine to performoperations comprising: acquiring images of a subject, the imagesincluding a plurality of images of a portion of the subject at differenttimes; aligning an image of the portion of the subject such that eachpixel of the image corresponds to a same point on the subject over asequence of images of the portion; processing the sequence of imagesafter aligning the images such that data is extracted from the images;and presenting data corresponding to the subject on a display unit,following the processing of the sequence.
 20. A system comprising: animage acquisition system, the image acquisition system operable toacquire images of a subject including a plurality of images of a portionof the subject at different times; an alignment system operably coupledto the image acquisition system, the alignment system arranged to alignimages acquired by the image acquisition system such that, for eachimage, each pixel of the image corresponds to a same point on thesubject over a sequence of images of the portion; a processing systemoperably coupled to the alignment system and arranged to process theimages, after aligning the images, such that data is extracted from theimages; and a display system operably coupled to the processing system,the display system operable to present data corresponding to the subjecton a display unit following the processing of the images.
 21. The systemof claim 20, wherein the system includes: one or more sources arrangedto apply a set of temperature stimuli to the portion of the subject; theimage acquisition system arranged to capture the images of the portionat the different times with respect to application of the set oftemperature stimuli; and the processing system structured to determine astatus of the portion of the subject from processing the images afteralignment.
 22. The system of claim 21, wherein the processing system isoperable to determine a rate of warming the subject after the subjecthas been cooled.
 23. The system of claim 21, wherein the system includesa temperature controller to apply pulsed heating or cooling withdifferent durations to skin, including healthy skin and a lesion, theprocessing system arranged to analyze a differential temperatureresponse of the lesion and the healthy skin.
 24. The system of claim 21,wherein the processing system is operable to determine a presence ofmalignant cancer or a probability value indicating a chance ofmalignancy.
 25. The system of claim 20, wherein the image acquisitionsystem includes a plurality of imaging devices.
 26. (canceled)
 27. Thesystem of claim 20, wherein the alignment system is operable to use oneor more calibration markers applied to the subject to align the image ofthe portion of the subject.
 28. The system of claim 27, wherein the oneor more calibration markers are visible against the portion of thesubject in a wavelength range measured by an imagining device thatcaptures the images of the subject.
 29. The system of claim 27, whereinthe one or more calibration markers contain sharp corners resolvable inthe acquired images, the one or more calibration markers used inaligning the image of the portion of the subject.
 30. The system ofclaim 20, wherein the alignment system includes instructions to performa corner detection technique to extract sharp corners from the image.31. The system of claim 20, wherein the alignment system includesinstructions to perform a transformation that maps each feature of theimage to its correct location in a reference image.
 32. The system ofclaim 31, wherein the instructions to perform the transformation includeinstructions to use a homography to compute the transformation under anassumption that the subject is on a plane.
 33. The system of claim 20,wherein the processing system includes instructions to process thesequence of images including instructions to: for each selected point onthe subject, generate temperature vs. time data; fit a model to thedata; generate a list of discrete and continuous parameterscorresponding to the temperature vs. time data at each selected pointusing the model; and use one or more segmentation/clustering techniquesto classify different parts of the subject.
 34. The system of claim 33,wherein the instructions to use one or more segmentation/clusteringtechniques include instructions to classify points on skin as healthytissue or malignant tissue.
 35. The system of claim 20, wherein thedisplay system is operable to present the data by color-coding theimages on the display unit, using a n-dimensional parameter spacegenerated from processing the sequence of images after aligning theimages.
 36. The system of claim 20, wherein the display system isoperable to rotate, on the display unit, an image of a skin subject suchthat the skin subject is viewable from different directions.
 37. Thesystem of claim 20, wherein the display system is operable to presentthe data on the display unit displaying visualization data of a skinsubject such that the visualization data is aligned to a scan of abiopsy of the skin subject corresponding to the visualization data ofthe skin subject.